Variable directional thrust for helicopter tail anti-torque system

Abstract

The present invention includes an anti-torque assembly for a helicopter comprising a plurality of fixed blade pitch motors mounted on one or more pivots on the tail boom of the helicopter, wherein the plurality of fixed blade pitch motors on the one or more pivots are adapted to be oriented substantially in-plane with a tail boom of a helicopter during a first mode of operation that comprises a hover mode and wherein the fixed blade pitch motors are adapted to be oriented substantially off-plane from the tail boom of the helicopter during a second mode of helicopter operation that is different from the first mode.

What is claimed is: 
     
       1. An anti-torque assembly for a helicopter having a tail boom and one or more pivots on the tail boom, the anti-torque assembly comprising:
 a plurality of electrically driven, variable-speed motors mounted on the one or more pivots on the tail boom of the helicopter, wherein each electrically driven, variable-speed motor drives a fixed blade pitch rotor and the plurality of electrically driven, variable-speed motors on the one or more pivots are adapted to be oriented substantially in-plane with the tail boom of the helicopter during a first mode of operation that comprises a hover mode and wherein the fixed blade pitch electrically driven, variable-speed motors are adapted to be oriented substantially off-plane from the tail boom of the helicopter during a second mode of helicopter operation that is different from the first mode; and 
 wherein each electrically driven, variable-speed motor is independently controlled. 
 
     
     
       2. The module of  claim 1 , wherein the plurality of electrically driven, variable-speed motors can operate: in a different direction from the other motors to provide opposing thrust; with the thrust in the same direction; with different speeds; or with different directions and speeds. 
     
     
       3. The module of  claim 1 , wherein the plurality of electrically driven, variable-speed motors comprise 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, or more electrically driven, variable-speed motors, and each motor can be: turned on or off independently or as a group; or each motor can independently direct thrust in a different direction. 
     
     
       4. The module of  claim 1 , further comprising a ring or cowling that surrounds one or more of the individual electrically driven, variable-speed motors and rotors of the anti-torque assembly, each ring or cowling being attached to a separate pivot, or the anti-torque assembly is surrounded by a single ring or cowling that is attached to the pivot. 
     
     
       5. The module of  claim 1 , wherein the anti-torque assembly is substantially co-planar with the tail boom during the hover mode. 
     
     
       6. The module of  claim 1 , wherein the second mode of helicopter operation is a flight mode, and wherein the anti-torque assembly is substantially perpendicular with the tail boom during the flight mode. 
     
     
       7. The module of  claim 1 , further comprising a logic in a flight control computer that calculates a direction and a thrust from the anti-torque assembly system during a transition to and from the first to the second mode of operation, and independently controls fan direction and speeds for the electrically driven, variable-speed motors to position the anti-torque assembly system for an optimum thrust angle, as well as an optimum thrust magnitude. 
     
     
       8. An anti-torque assembly system for a helicopter, the system comprising:
 a plurality of electrically-driven, variable-speed motors mounted on one or more pivots on a tail boom of the helicopter, wherein each electrically driven, variable-speed motor drives a fixed blade pitch rotor; 
 one or more drive mechanisms to orient the electrically-driven, variable-speed motors to be substantially in-plane with the tail boom of the helicopter during a first mode of helicopter operation that comprises a hover mode and that orients the electrically-driven, variable-speed motors substantially off-plane with the tail boom of the helicopter during a second mode of helicopter operation that is different from the first mode, wherein the second mode of helicopter operation is a flight mode; and 
 wherein each electrically driven, variable-speed motor is independently controlled. 
 
     
     
       9. The system of  claim 8 , further comprising a logic in a flight control computer that calculates a direction and a thrust from the anti-torque assembly system during a transition to and from the first to the second mode of operation and independently controls fan direction and speeds of the electrically-driven, variable-speed motors, and to position the anti-torque assembly system for an optimum thrust angle, as well as an optimum thrust magnitude. 
     
     
       10. The system of  claim 8 , wherein the first mode of helicopter operation is a hover mode, and wherein the one or more drive mechanisms are configured to orient the anti-torque assembly system to cancel the torque of a rotor blade of the helicopter during the hover mode. 
     
     
       11. The system of  claim 8 , wherein the drive mechanism is configured to orient the anti-torque assembly system to be substantially perpendicular to the tail boom during the flight mode. 
     
     
       12. The system of  claim 8 , wherein the drive mechanism comprises an electric drive mechanism that rotates the anti-torque assembly system from the first to the second mode and vice-versa. 
     
     
       13. The system of  claim 8 , further comprising a mounting system to mount the anti-torque assembly system to a tail boom of the helicopter. 
     
     
       14. The system of  claim 13 , wherein the mounting system is attached to the pivot, wherein the pivot is offset from the tail boom to allow the anti-torque assembly system to be rotated between the hover and the flight mode. 
     
     
       15. The system of  claim 13 , wherein the mounting system includes a fork attached to the tail boom, wherein the anti-torque assembly system is mounted to the fork. 
     
     
       16. The system of  claim 15 , wherein the fork includes an upper end and a lower end attached to an upper pivot position and a lower pivot position, respectively, of the anti-torque assembly system, and the lower end of the fork is thicker than the upper end of the fork. 
     
     
       17. A method of operating a helicopter, the method comprising:
 orienting an anti-torque assembly comprising two or more electrically-driven, variable-speed motors on a pivot at the end of a tail boom of the helicopter, wherein each electrically driven, variable-speed motor drives a fixed blade pitch rotor and the two or more electrically-driven, variable-speed motors are substantially in-plane with the tail boom of the helicopter during a first mode of helicopter operation that comprises a hover mode and wherein the two or more electrically-driven, variable-speed motors are substantially off-plane with the tail boom of the helicopter during a second mode of helicopter operation that is different from the first mode, wherein the second mode of helicopter operation is a flight mode; and 
 wherein each electrically driven, variable-speed motor is independently controlled. 
 
     
     
       18. The method of  claim 17 , wherein the second mode of helicopter operation is a flight mode, and wherein the anti-torque assembly is substantially perpendicular with a plane of rotation of the tail boom during the flight mode. 
     
     
       19. The method of  claim 18 , further comprising adjusting an orientation of the anti-torque assembly in the flight mode to adjust at least one of a pitch, roll or yaw of the helicopter using one or more of the individual electrically-driven, variable-speed motors. 
     
     
       20. The method of  claim 17 , further comprising calculating, using a logic in a flight control computer, a position of the anti-torque assembly during a transition to and from the first to the second mode of operation and independently controlling individual electrically-driven, variable-speed motors to position the anti-torque assembly and an output from the electrically-driven, variable-speed motors for an optimum thrust angle, as well as an optimum thrust magnitude.